[Circulatory changes in the sitting position during neurosurgical anaesthesia (NLA) (author's transl)].

In 23 neurosurgical patients with haemodynamic effects of neuroleptanaesthesia in the supine (13 patients) and upright position (10 patients) were studied. The patients in the upright position demonstrated an increase of the mean arterial pressure of 19% and the total peripheral resistance of 45%, and simultaneously a decreased stroke index of 20% and the cardiac index of 16%. The stability of the circulation was preserved due to the increase of heart rate (to 90 +/- 17 beats/min) and total peripheral resistance. In spite of the almost identical average total dose of fentanyl in both groups (4.72 +/- 2.2 mcg/kg/h), supine position) and 4.97 +/- 2.23 mcg/kg/h, (sitting position), only the patient group in the supine position demonstrated a decrease of pulse rate of 36% to 65 +/- 20 beats/min with a decline of the cardiac index of 33% and unchanged stroke index. Our clinical observations and the animal studies of other authors allow the conclusion that during neuroleptanaesthesia in the upright position the baroreceptor-activity and the catecholamine secretion is not markedly reduced and consequently circulatory stability obtained. We regard neuroleptanaesthesia as the method of choice for neurosurgical operations in the upright position.